i486

The i486, officially known as the Intel 80486, is a 32-bit microprocessor introduced by Intel in 1989. It was the successor to the i386 and brought significant performance improvements and new features. A key advancement was the integration of an on-chip floating-point unit (FPU) and an 8KB cache memory. This eliminated the need for separate coprocessor chips, simplifying system design and boosting performance in applications that relied on floating-point calculations.

The i486 also featured a pipelined instruction execution, allowing it to process instructions more efficiently than its predecessors. This, combined with a higher clock speed than the i386, resulted in a noticeable performance increase, often quoted as being roughly twice as fast as an i386 at the same clock speed. The i486 was available in various clock speeds, starting from 25 MHz and going up to 100 MHz.

The i486 architecture was a significant step towards modern processors, laying the groundwork for subsequent Intel processors like the Pentium. It was widely adopted in personal computers during the early to mid-1990s and powered a generation of operating systems and applications. Variants of the i486, such as the i486SX (without the FPU) and the i486DX2 (with an internal clock doubler), were also released to cater to different market segments and performance needs. Its success cemented Intel's dominance in the microprocessor market for many years.